Method of purifying, concentrating, and converting petroleum sulfonates



Sept. 14, 1954 U B BRAY 2,689,221

METHOD OF PURIFYING, CONCENTRATING, AND CONVERTING PETROLEUM SULFONATES Filed June 13, 1950 6 Sheets-Sheet 1 Sept. 14, 1954 u. B. BRAY 2,689,221

METHOD oF PURIFYING, CONCENTRATING, AND CONVERTING PETROLEUM sULFoNATEs Filed June l5, 1950 6 Sheets-Sheet 2 TREATMENT wmv WATER i 55C. .Bun/L ALCOHOL A7' /45 F 5y His A rive/V675 Sept 14, 1:1954 U.. B; BRAY 2,689,221

METHOD OF PURIFYING,v CONCENTRATING, AND

CONVERTING PETROLEUM SULFONATES Filed June 13, 1950 6 Sheets-Sheet 3 HEAT/VENT W17# M4761? 55C. l/TYL ALCOHOL A7' /65 "F SALE 3 l 'f OIL g4. I

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PARTS EUECTED UIL LAYER 30 40 50 PARTS H30 /00 PARTS @y l/Ol. SOAP- OIL /N STOCK PARTS REJECTED OIL LAYER /5 /.3 H2O by ro PAIS' R//VE LAYER Z 3 4 5 6' 7 8 9 l0 /l /Z /3 /4 PAATJ /002 B A. by 00A Pf?? /00 PARS SOAp- O/L /NJTOCK 5y H/s A Troia/srs /914/89/5 //Ec/f; FJ- Tee q HAP/Qns N I l Sept. I4, 1954 U. B. BRAY 2,689,221

METHOD OF PURIFYING, CONCENTRATING, AND

CONVERTING PETROLEUM SULFONATES Filed June 13, 1950 6 Sheets-Sheet 4 TREATMENT WITH WATER 555C. @(/TYL ALCOHOL AT /0OF PARI-5 Rez/Ecrin 0/1. LAVE@ D l PAQTS H2O by l/O/ n n n n l .5 6 8 9 /0 l2 /3 PARIS loo?, 5.6.4 ay val. p51? /oo f7/m75 SOAP- o/ /zv smc-K Sept. 14, 1954 u. B. BRAY METHOD OF' PURIFYI 2, 689,2 2 1 NG, CONCENTRATING, AND CONVERTING PETROLEUM sULFoNATEs 6 Sheets-Sheet 5 Filed June 13, 1950 out 6 um. ..50

Sept. 14, 1954 u. B. BRAY METHOD OF' PURIFYI AND NG, CONCENTRATING CONVERTING PETROLEUM SULFONATES 6 Sheets-Shel#I 6 Filed June 15, 1950 Patented Sept. 14, r1954 NATES UlricB. Bray, Pasadena, Calif., assignor to Bray Oil Company, Los Angeles, Calif., a limited partnership Application llinieV 1'3, 1950, Serial No. 167,798'

17 Claims. l

This. invention relates to the purification and concentration of hydrocarbon sulfonates of the oil-soluble or mahogany acid type, and to the conversion of these sulfonates to polyvalent metal sulfonates.

In the preparationY of some rust preventing compounds and` lubricants, and in the preparation of some lubricants for severe service uses and for similar lubricating uses, it has been a practice for many years to employ various metal salts or sulfonic acids derived from the reaction of sulfuric acid and. petroleum fractions in the lubricating oil range. These sulfonic acids, and their salts are well known. in the petroleum industry. Those most commonly used for the pres ent purpose are the oil-soluble acids known as mahogany acids. which are found in solution in a supernatant oil layer which accumulatesl above an acid sludge layer upon settling or a batch of petroleum lubricatingV oil following sulfuric acid treatment. The sulfuric acid treatmen-t of petroleum lubricating oil resultsk also in the production of other sulfonic acids, known as green acids, which are primarily water-soluble and are, therefore, found chieily in the acid sludge layer. However, some of these water-soluble green. acidsy are found in the presence of the oil-soluble' mahogany acids in. the oil layer and are objectionable for certain purposes. Possibly these vagrant Water-soluble sulfonic acids pass intov the oil layer because they are at the same time slightly oil-soluble, or because they are to that extent solubilized by thev action of the mahogany acids, or because of the failure to remove l the last traces of pepper sludge from the acidtreated oil. As a result, these objectionable Wa,-

ter-soluble green acids are carried over as sulionate into the oil-soluble sulfonate` which is commonly placed upon the market as the sodium salts of the mahogany acids, For the purpose of preparing rust preventing compounds and severe service lubricants, theseV sodium mahogany acid salts are commonly converted bymetathesis into objectionable inY rust preventivos and in lubricating oilsI Where moisture maybe encountered, because they appear toA weaken the resistance to=waterof an oil film onmetal, possibly through favoring the formation of a Water-continuous emulsion.; whereas the water-insoluble, oil-insoluble calcium saltsof the true mahogany acids, when operating in the presence of water to form emulsions, result in emulsions Where oil is the continuous phase. In the case of oil-continuous emulsions, the oil preferentially Wets iron or steel surfaces with the result that the water present in the emulsion does not Wet the metal. and rusting is avoided. On the other hand, Where the chemical environment produces Water-continuous emulsions, the Water phase displaces the oil from the metal surface, thereby reducing or destroying the rust inhibiting effect of the oil. Even though the oil-soluble, Water-insoluble sulfonates greatly predominate, nevertheless, appreciable proportions` of Water-soluble sulfonates result in undesirable effects when the polyvalentmetal sulfonates are used as detergent additives or rust preventives in lubricants. For example, even a relatively small proportion of the Watersoluble sulfonate results in excessive Water corrosion, to the extent that products fail to give the full degree of protection required in severe service, such as in military and naval operation.

In my prior Patent 2,453,690 entitled Process of Producing Polyvalent-Metal Hydrocarbon Sulfonate,` issued November 16, 1948,. I disclosed a process of converting and treating oil-soluble, Water-insoluble, polyvalent-metal petroleum sulfonates, such as calcium petroleum sulfonate in oil in the presence of water with an oil-soluble, liquid, emulsion-breaking, organic compound, such as a butyl, amyl, or heXy-l alcohol, whereby to break the resultant emulsion, to cause much of the objectionable water-soluble green acid sulfonates to separate in a resultant Water layer and-thereby correspondingly purify the oil solution of theY desiredv oil-soluble mahogany acid sulfonates, and to provide for separation of objectionable water-insoluble, inorganic salts, such as resultant calcium sulfate, which was accomplished by filtering the resultanty oilsulfonate layer in the presence of a filter aid, or the like.

It is an important objectof the present invention to purify alkali-metal mahogany sulfonates by ridding them ofthe mentioned objectionable substances, to concentrate such mahogany sulfonates with respect to oil by eliminating excessoil therefrom, and then to convert to polyvalentmetal forms the mahogany sulfonates so-puriiied and concentrated in order that they may be use'- ful in corresponding rust preventives and detergent lubricating oil.

Another object is to separa-te the green acid sulfonates and inorganic sulfates or other inorganic salts which would form insoluble salts with calcium or other polyvalent metal to be used, as water-soluble forms in a water and emulsionbrealing liquid layer from which the oil and water-soluble, alkali-metal mahogany sulfonates present are caused to separate.

It is also an object to provide a process for recovering oil-soluble, water-insoluble, polyvalent-metal sulfonates, such as calcium mahogany sulfonates, in oil, whereby excess oil beyond that desired in a given product s easily rejected in the presence of water and an oil-soluble, emulsion-breaking, organic liquid, such as an amyl, hexyl, or butyl alcohol. A particular object is to remove excess oil before conversion of the mahogany sulfonate to the water-insoluble. polyvalent-metal form.

It is also an object to separate the objectionable inorganic salts mentioned in a water-soluble form whereby to avoid the necessity of subsequently filtering their insoluble forms from the oil-sulfonate product, and whereby to reduce employment of lter aid and the like and the incidental costs thereof.

It is a still further object of the invention to provide a process for the recovery of petroleum sulfonates whereby formation of difliculty breaking emulsions, such as the large so-called cu-lf layers, is avoided.

Still another object of the invention is to provide a process for the treatment of crude petroleum sulfonates containing excessively large percentage amounts of. petroleum oil, appreciable amounts of water and objectionable inorganic salts and green acid sulfonates, whereby the objectionable materials and excess petroleum oil are easily eliminated.

Thus, individual objects are: to eliminate all green acid sulfonates; to eliminate all objectionable inorganic salts easily and without excessive employment of filter aid; to eliminate easily any proportion of excess oil from the sulfonates; and to provide such a process adaptable to the usual crude sodium sulfonates containing, for example, up to 80% or 85% mineral oil of various lubricating viscosities and from perhaps to 50% or 60% water based on oil-sulfonate content along with 1% to 5% of inorganic salts such as sodium sulfate and sulflte.

It is also an object to purify and/or concentrate crude alkali-mahogany sulfonate for use as emulsifying and wetting agents or for other known uses to which sodium, potassium and/or ammonium hydrocarbon sulfonates and sulfates are put.

It is also an object to provide a purification, concentration, and conversion process for crude sulfonates of the indicated character whereby *very large batches of crude material of high oil content and relatively low sulfonate content may be so treated with relative ease, as against treatment of only relatively small batches as heretofore.

Other objects of the invention will become apparent from the following description, as will the various features of the invention. In connection with the following specification reference is made to the accompanying drawings wherein:

Fig. l is a iiow diagram representing the major steps of the process when operated batchwise;

Figs. 2, 3, and 4 present curves for secondary butyl alcohol treatments at 145 F., 185 F. and 100 F., respectively, which curves show various relationships among various component mateof which the sulfate predominates.

4 rials present during the operation of the process:

Fig. 5 is a ilow diagram representing the principal steps of the process when operated continuously in single or multiple stages; and

Fig. 6 is a flow diagram representing the principal steps of the process when operated countercurrently.

Throughout this specification, the term waterinsoluble is intended to signify relative insolubility, that is, entire immiscibility or only partial miscibility under the conditons employed, as contrasted with complete miscibility in any proportion. The term Water-soluble is used to signify either true (complete) solubility or a high state of dispersion which approaches true solubility and is adequate for the respective purpose. The term oil-soluble signifies substantially true or complete solubility of the respective material in the hydrocarbon oil present or a high state of dispersion approaching such true or complete solubility. The term soap will sometimes be used to signify the respective sulfonate. Where reference is made to removal or elimination of green acid soaps or inorganic salts, such terminology is intended to include either complete elimination or reduction of the respective materials to such insignificant proportions that the presence of the remainder does not interfere seriously with subsequent processing or is not detrimental for uses to which the sulfonate product is eventually to be put. Where the term concentration is used, it refers to the concentration` of the sulfonates with respect to the oil present unless some other meaning is obvious.

In treating crude petroleum sulfonates. various crude materials are encountered, all of which are amenable to the process of this invention. These crude sulfonates commonly contain between 30% and 85% petroleum oil of various lubricating viscosities, various sulfonate contents between about 10% and about 60% soap including between about one-half per cent and 3% green acid soaps, and from 1% to 5% (for example, 3%) of sodium sulfate and sodium sulte The sulfonates are commonly salts of the alkali metal sodium and are Water-soluble. They are to be purified to eliminate the green acid soaps, the sultes and sulfates mentioned, the water, and any proportion of the oil which is not desired in the final product and which will be ordinarily referred to herein as excess oil. The green acid soaps are to be removed because of their deleterious effects in the end products, and the sulfates and sultes are to be removed because they interfere with the emulsifying properties of the sodium sulfonate and constitute impurities therein if permitted to remain. In addition, if these inorganic sulfates and sultes are retained, they are converted into insoluble polyvalent-metal compounds in the conversion stage and settle to the bottom of the treating tank as a mud which, in the presence of the sulfonates, is coated with considerable quantities of oil because of the wetting properties of the sulfonates and presents here the problem of difficult separation or the element of unnecessary loss of a substantial proportion of oil and sulfonate.

My present invention involves certain new discoveries that I have made. Thus, I have found that, at appropriate temperatures, I am able to purify crude, water-soluble, alkali-metal sulfonates before conversion to the Water-insoluble, polyvalent-metal forms by commingling them with controlled proportions of water and of an emessi emulsion-breaking, oil-soluble, relatively waterinsoluble organic liquid, the objectionable inorganic salts and green acid sulfonates passing into a water layer which settles out as a brine upon standing. Such treatment may be effected with very large gallonage and is facilitated where the water is present as aV weak sodium chloride solution, for example a solution.

I have also discovered that excess oil may be separated from the water-soluble alkali-metal sulfonate by controlling the proportions of water and emulsion-breaking liquid respectively to the soap-oil content of the cruder sulfonate. Gen-l erally, by holding the proportion of emulsionbreaking liquid constant at a low level between dand volumes per 100 Volumes of soap-oil mixtureY (reckonedtogether) in the crude stock and adding water in increasing amounts, rst a brine phase appears which settles tothe bottom and maybe drawn off as indicated above. Further additions of water cause an oil phase to appear whichr rises to the top and is readily separated from the then concentrated soap layer. This rejected oil phase contains only a fraction of a percent of soap but does contain a few percent of the emulsion-breaking liquid and water. The rejection of the excess oil is increased as the proportion of either the emulsion-breaking liquid or water, or both, is increased, and appears to be practically independent of whether or not the brine phase is removed as soon as it appears; but unless the brine phase is removed after appearing, it will go back into solution upon further addition of alcohol and water.

The production of both a brine layer containing undesirable inorganic salts together with green acid soaps and a rejected oil layer containing excess oil can often be accomplished in. one step by careful selection of the treating doses of water and emulsion-breaking liquid, respectively. However, for greatest flexibility and ease of operation by less skilled personnel, it is usually preferredfto conduct the purification and oil separation as separate steps, differing from each other mainly in the amount of water present. Reference to Figs. 2 and 3 will show for example that, with a given amount of secondary butyl alcohol within a suitable range with respect to the oil-soap content of the stock, a brine layer will appear upon increasing the water present (curves B) before a rejected oil layer will appear (curves A). However, continued increase of the water beyond a certain point causes the brine layer to decrease and eventually disappear; Whereas when the critical amount of water has been reached to cause appearance of a rejected oill phase, further additions of water cause increasing amounts of oil to be rejected and the total amount of oil rejected tends ultimately to approach asymptotically the total amount of oil present in the stock. Likewise, as shown in Figs. 2, 3` and 4 (curves C and D), at a given water contentup to a certain point, the yield of brine phase increases slightly with alcohol dosage, but beyond this point increasing dosages of alcohol resoap-oil concentrate layer which; contains thev water and the emulsion-breaking liquid, may be easily converted to water-insoluble, oil-soluble, polyvalent-metal soap by mixing therewith a water solution of a salt of an appropriate polyvalent metal, the mixturev being allowed to stand at appropriate temperatures for a moderate time whereupon sharp separation results between the polyvalent-metal soap and oil layer and the aqueous layer.

It is apparent that my invention comprises. a complete process whereby the crude mahogany acid sulfonates are (1) purified by removing inorganicsalts and green acid soaps in the form. of an aqueous brine, (2) concentrated by rejecting and removing excess oil, and (3) converted to polyvalent-metal sulfonates. These three steps are eiiciently controlled by the proper adjustment of three variables; namely, variation of the proportion of water, as above indicated, employment of an appropriate proportion of emulsion-breaking liquid, and operation at a suitable temperature.

Generally temperature is not a critical variable; however, temperature ranges in the neighborhood of F. to 150 F. when the various operations are conducted batchwise and F. to 200 F. when conducted in a continuous manner, for each of the purication, concentration, and

conversion steps are conveniently employed.

each 100 parts of soap-oil (reckoned together) in the crude stock to remove objectionable inorganic salts, sodium sulfate and sodium sulte, and the undesired green acid sulfonates. In the concentration stage, additional water is supplied if insuicient excess oil has been rejected during the purification step. Ordinarily, 30 to 50 parts of water total per 100 parts of soap-oil (reckoned together) in the crude stock to be treated will give suitable rejection of excess oil.

Additions of either water or the emulsionbreaking organic liquid or both to a mixture whose composition is in the range for oil rejection will disturb the solvency equilibrium and cause additional rejection of oil into the supernatant layer. The resultant underlying concentrated soap layer (soap concentrated with respect to oil) may thus be made to contain oil in that proportion desired in the final product.

I have discovered that instead of using practically pure water (city drinking water), along with the emulsion-breaking liquid, to wash out water-soluble impurities from a crude sodium sulfonate-oil mixture, I can advantageously use an aqueous salt solution in many instances. it is expected that purified sodium sulfonate will subsequently be converted to calcium, barium, or strontium sulfonate, it is very desirable to remove sulfates and sultes as far as practical to avoid formation of the water-insoluble sulfates and sulfites of these polyvalent metals during the conversion of the soap. The presence of anions which do not give water-insoluble salts with the poly- Where v valent metals is not objectionable from this standpoint, such anions being chlorides, nitrates, acetates, etc. Therefore, if the presence of these anions in the Wash Water elects greater removal of the sodium sulfate and sulte in the brine layer during the purification step, their use is often justified. In general, chlorides of the monovalent metals are preferred, especially sodium chloride because of both its efciency and relatively low cost. When using sodium chloride solution in place of water during purification, the same behavior is obtained as is illustrated by the curves in Figs. 2, 3, and 4, except that the amount of brine phase settling out for a given dosage of alcohol andwater, respectively, is both larger in volume and more concentrated in sulfates and sultes.

If a purified concentrated alkali-metal sulfonate is desired as the end product, the concentrated soap layer is simply distilled to remove water and the emulsion-breaking organic liquid, and the resulting residue is recovered, with or without i'lnal purication by i'lltering or centrifuging while heated.

If a puried concentrated polyvalent-metal sulfonate is desired as the end product, the concentrated soap layer is reacted with an appropriate water-soluble polyvalent-metal salt such as calcium chloride. Usually the polyvalent-metal salt is added in the form of a concentrated aqueous solution, but with proper agitation the solid salt in the form of flakes, powder, or crystals, may be added directly to the concentrated soap layer. On account of the presence of the emulsionbreaking organic liquid, the reacted mixture straties readily into a converted soap layer, containing also the remaining oil and most of the emulsion-breaking organic liquid, and an aqueous phase containing Icy-product salts, excess reagent salt, and a very small proportion of emulsionbreaking organic liquid. The converted soap layer is separated and distilled to recover emulsionbreaking organic liquid and finally dehydrated and recovered as the end product after filtering or centrifuging while heated.

While temperatures are not particularly critical, asV mentioned before, nevertheless, at temperatures materially below 140 F., viscosity conditions become a consideration because they delay phaseA separation, and at low temperatures such as around 100 F., the separation of the various phases is inconvenientlyA slow. However, if the time element is of little consequence, temperatures may be used down to 100 F., for example,

withoutdifculty, as is apparent from the curves of Fig. 4. While temperatures as high as 185 F. and up to about 200 F. produce rapid settling, they, nevertheless, may complicate the matter of maintaining adequate concentration of the emulsion-breaking liquid in batchwise operations. Therefore, a temperature of about 145 F., or from about 140 F. to 150 F., has been found to be a desirable optimum and representativeY of a good compromise between speed of separation and settling of the layers and retention of emulsion-breaking liquid in the batches during such separation and settling. Discussion of preferred temperatures in continuous operations is given below.

With respect to the emulsion-breaking liquid, this may be any oil-soluble, at least partially water-soluble organic liquid consisting of carbon, hydrogen and oxygen of suiciently low boiling point to facilitate its removal and recovery from the various phases and of sufficiently low viscosity not to Vdisturb kseriously the various operations. Thus, any such oil-soluble, partially water-soluble liquid consisting of carbon, hydrogen, and oxygen and possessing four to about eight carbons per molecule is useful. VBy suitable boilingpoint, it is intended to signify a boilingpoint below the decomposition point of the sulfonates so that the diluent liquid may be eliminated from thev product by vaporization. In general, this signies a boiling point not materially in excess of 400 F., inasmuch as the initial decomposition temperature of a sulfonate, such as calcium sulfonate, is in the neighborhood of 450"Y F. to

500 F. Y Y e This class of emulsion-breaking organic liquids, is at present best represented by the hexyl, amyl and butyl alcohols, for example, methylisobutyl carbinol, iso-amyl alcohol (pentasol for example), and secondary butyl alcohol. These materials have suitable boiling ranges, and are partially water-soluble in water, for example, about 2% solubility in water for methyl isobutyl carbinol and about 12% for secondary butyl alcohol, and are preferentially oil-soluble. However, other alcohols that may be employed are the heptanols and the octanols. Hereafter, the emulsion-breaking liquid ordinarily will be referred to as' alcohol, with theabove alcohols in mind, especially hexyl alcohol or butyl or secondary butyl alcohol, the latter being now commonly employed by me in commercial operation. Examples of emulsion-breaking liquids other than alcohols are mesityl oxide, isopropyl acetate, isobutyl ace-Y tate, isopropyl ether, and methyl isobutyl ketone.

Having reference to the accompanying batch flow diagram of Fig. 1 vand also to a particular crude alkali-metal sulfonate (Code No. 8f3-H) asA an example of various crude sulfonates whichv have been successfully treated, a preferred method of procedure, which embodies the various aspects of this invention is set out below'.

VThe foregoing crude alkali-metal (sodium)y sulionate (Code No. Sii-H) contains about 4% i water, 16% total sulfonates,77% oil, and 3% inorganic salts. The inorganic salts are prin-r` cipaliy sodium sulfate with a very minor portionv of sodium sulte, both of which'ar'e to be' removed by this method'.V The total sulfohate con; tent consists of 14.5% mahogany acid soap and" 1.5% green acid soap. Itis desired to'remove` the 'green acidsoapwithout'loss of mahoganyacid soap.n It is desired also to remove 'excess oil and produce a concentrated calcium 'sulfonate containing 40% soap. It is further desired'to' convert any trace'of sodium sulfonate appearing in the removed oil to calciumsulfonate in order that the removed oil may be used i'n'frmulating engine oils, rust preventive oils, etc.

Purification stage-To the particular starting material, above described, water is added in an amount'equal to approximatelyvv 20% of the crude stock, corresponding to 21.5% vbased'on the oil" soap contentA of the crude stock. Preferably ai 5% sodium chloride solution isV employed be' cause the sodium chloride serves efficiently to displace the sodium sulfate and the sodium vsulte so that the latter salts will come out in a settled brine layer. used, the less eiciently arethesultes'and sulv fates eliminated. YWhile stronger concentrations' oi sodium chloride may be employed,"10% or'15% for example, to obtain greater removal of sulfatesand sultes, the additional cost is usually not Yconsidered justied; 'This'is particularly because'the amounts of sulfates and-sultes which` The less Vsodium chloride' are not removed by employment of a sodium chloride solution in the proper dosage are insufficient to detract seriously from the usefulness of the purified sodium sulfonate as such or as a raw material for making polyvalent-metal sulfonate.

To the crude sulfonate stock there is also added, between about 5% and about 15% of the selected emulsion-breaking organic liquid described, such as secondary butyl alcohol based on the crude stock. Hereinafter such material will be referred to merely as the alcohol. In using secondary butyl alcohol, the alcohol is usually saturated with water and contains about 30% to 35% water. Appropriate allowance is made for such water content of the alcohol in formulating the treatment of a batch of stock.

In a partciular instance, 32,203 gallons of the described crude sodium sulfonate stock containing about 16% total soap and about 4% water were pumped into a treating tank in admxture with 6,632 gallons of 5% sodium chloride solution containing 700 lbs. NaOH (the latter required to insure neutrality or slight alkalinity during the processing) and 4,858 gallons of the mentioned 65% to 70% secondary butyl alcohol. As is represented in the batch flow diagram of Fig. 1, the sodium chloride solution and the alcohol are introduced by pumps into the crude sulfonate stream on its way to a heater I0 in which the mixture is heated to about 150 F. and from which it is passed into a 60,000-gallon tank I2. When the entire batch is charged, it is agitated for 20 to 50 minutes to insure equilibrium between all components.

The heated and agitated mixture in tank I2 is then allowed to stand and settle for several hours, for example over night, or other appropriate period of time which may range from four or ve hours up to any other desired time. During this interval the temperature gradually drops with this volume of material to about 140 F., the temperature, however, being at all times adequately high to assure good separation of a water (brine) phase which settles out in the bottom of the tank, as indicated, and carries with it all objectionable proportions of green acid soaps, sodium sulfite and sodium sulfate, and

similar objectionable inorganic salts.V Not only do the sultes and sulfates separate in the lower brine layer, but the green acid sulfonates are also carried down in this brine layer because apparently they are preferentially soluble in the water of the brine layer, whereas the mahogany acid sulfonates which remain in the supernatant layer are preferentially soluble in the oil and in the oil-soluble alcohol.

The temperature range of 140 F. to 150 F., above indicated, has the further advantage that the separation of alcohol vapors is small. In practice such vapors as do accumulate in the top of the tank are conducted to an alcohol recovery system.

After sucient standing and settling, the separated brine layer is withdrawn from the bottom of the tank. In the particular example above given, the brine layer measured 6,102 gallons, and the oil-soap-alcohol layer measured 39,551 gallons, both at 137 F. Preferably the withdrawn brine is passed to a still and the dissolved alcohol driven oif and recovered.

Concentration Stuga-The above described supernatant layer containing the oil, alcohol, and mahogany soap is passed from the tank I2 through a heater I4 and upon its way to the heater is mixed with a quantity of tap water sufcent to unbalance the previous solvent relationship between the oil,.soap, and alcohol so that upon further standing and settling any desired proportion of the excess oil in the soapoil-alcohol layer is rejected depending on the amount of water added. In the specific instance 6,400 gallons of water equal to 20% of the original charge of crude stock was introduced. In the heater I4 the soap-oil-alcohol mixture with the added water is raised to a temperature of about 150 F. as before, and this mixture is then either returned to the tank I2 or passed to another tank I5 as indicated in the flow diagram, where it is agitated to insure equilibrium being established again.

In the tank l5, the heated mixture is again allowed to stand and settle over night, or for several hours, so that the oil rejected by reason of the change in the solvent relationship separates as a supernatant layer above a soap-oil concentrate containing the alcohol and the water. In the example described above, where the crude stock contained 77% oil, approximately 90% of the oil in the crude stock was rejected into the supernatant layer, while 10% of the oil in the charge remained in the underlying soap layer. In eifect, oil appears to be rejected under a given set of conditions until the ratio of soap to oil in the soap containing phase satisfies the equilibrium requirements for that set of conditions (apparetnly without regard to the quantity of oil in the original charge of stock). Obviously, if the proportion of oil to soap is already below the equilibrium requirements, no oil will be rejected under that particular set of conditions. As more water and alcohol are added, however, a point will be reached where oil will be rejected. I have thus been able to concentrate alkali sulfonate to a degree where only 22 parts of oil remained for each '78 parts of sulfonate.

In the foregoing example of a batch being processed, the rejected oil layer gaged 26,085 gallons and the soap layer gaged 20,530 gallons, each at F.

Conversion stagna-The aqueous soap concentrate (containing alcohol and some oil) which settles out in the tank I5 is next subjected to treatment to convert the alkali-metal, watersoluble, oil-soluble, mahogany sulfonate into a water-insoluble, oil-soluble, polyvalent-metal sulfonate. This is accomplished by passing the settled layer of the soap-oil concentrate from the bottom of the tank I5 to a heater I6 to restore its temperature, and by commingling this concentrate with a water solution of an appropriate polyvalent-metal salt. Commonly, calcium sulfonates are produced, and for this purpose a 30% to 50% solution of calcium chloride in water is used, this solution being commingled with the soap-oil concentrate as it is passed to the heater I whereby to raise the temperature of both the calcium chloride solution and the concentrate to about F. If the rejected oil has been removed from the tank I5 (or tank I2) to some other tank, such as tank i8, the mixture heated in the heater I0 may be returned to the tank I5 (or the tank I2) or it may be passed to a conversion tank 20. As before, the heated mixture is allowed to stand and settle for several hours, or over night, whereby a water solution containing excess calcium chloride and sodium chloride settles out to leave a clear, supernatant layer of calcium sulfonate concentrate in oil together 1'1 with the bulk ofthe alcohol and a limited amount of entrained` or dissolved water.

In operating with the original 32,203 gallons of crude sulfonate of the above example, the amount of calcium chloride used to convert the mahogany sulfonate in the concentrate was 9,660 pounds which was dissolved in 1,453 gallons (121,108 pounds) of water.

In order to provide a consistent control of the concentration of the sulfonate in the end product, it has been found both easy and desirable to reject more oil than necessary during the rejection operation and then add back an appropriate amount of the same or another moredesirable oil at a later stage to regulate the soap concentration in the final product. Where the concentrated sodium sulfonate is to be converted to a polyvalent metal sulfonate, the concentration adjustingoil may be added before, during, or after the conversion to the polyvalent-metal sulfonate. In the above example, 1,044 gallons of the rejected oil phase was pumped into the conversion tank following the transfer of the concentrated sodium sulfonate phase to the conversion tank. The total charge in the conversion tank was gaged to be 21,954 gallons after settling over night, of which 12,561 gallons was an oil-soap layer and 9,393v gallons was a brine layer.

Normally, in the conversion stage it might be expected that, in view ofpast experiences, the calcium or other polyvalent-metal sulfonate formed in such concentrated oil solution would result in the production of. a very refractory waterin-oil emulsion. However, in conjunction with thedescribed alcohol or other emulsion-breaking, oil-soluble, water-insoluble, organic-liquid compound consisting of carbon, hydrogen and oxygen, the phases break readily and separate sharply within a few hours to yield an underlying brine layer of sodium chloride and calcium chloride in water with a sharply deiined supernatant layer of polyvalent-metal soap in concentrated condition in the oil present, together with the bulk ofthe emulsion-breaking liquid used and a proportion of water which is readily removable during a subsequent dehydration step. I have no particular theory regarding the action of the indicated class of organic compound. Apparently the function of the alcohol, or' other. emulsionbreaking liquid, is not soY much that of a selective solvent as that of breaking up an otherwise stable oil-continuous emulsion, or, possibly. that' of preventing formation. ofsuch an emulsion.

The', calcium soap-oil-alcohol layer is then passed-to a still 22`to distill off the alcohol, which is recovered andl sentv to storage, and to Vdehydrate the oil-soap concentrate to yield a finished product which may be placed inA storage, as in a receptacle 2li, either with or without filtering or other further treatment.

Inasmuch as the excess oil rejected in the concentration stage in tank l5 may contain a very smallamount of mahogany soap, this soap should be converted into calcium or other polyvalentmetal soap. Therefore, such oil, having been passed for example to the tank i8 for treatment, is recirculated through a heater 25 in admixture with the excess calcium chloride in the water solution drawn from the conversion tank 2:3, and the temperature again brought up to about 150 F. The heated mixture is allowed to stand in the tanki it until the water solution separates in the bottom and leaves a supernatant oil layer containing the small amount of resultant calcium sulfonate. Such oil, which is commonly of lubri- 12 eating viscosity, is: useful inV lubricating, rustpreventing, and other petroleum compositionsandis therefore dehydratedl and recoveredv asa valuable product.

By finishing the converted soap layer and the converted rejected oil layer separately by adding Ca(OH)z (calcium hydroxide) to insurel alkaline products', distilling to recover alcohol andY remove water, nally heating to approximately 309 F., and then filtering with the aid of a small amount ofv diatomaceous earth, aA yield'of alkaline calcium sulfonate'concentrate of 10,045 gallons having a sulfated ash value of 6.68% was obtained, and a yield of4 by-product (rejected) oil of 19,743 gallons having a sulfated:

to 15 based on the oil-soap content of the stock,

there is an appropriate range of Water content of the mix (the sum of'both the water present in the stock and the waterA added) for any givenv alcohol content. This appropriate water content of the mix will usually be found in the range ofr 10% to 60% water based on the oil-soap content of the stock. Furthermore, in the appropriate water range for any given alcohol dosage, there Will be a somewhat narrower preferred range of water content, as is to be expected from the fact that with water contents below and above the appropriate range, no brine phase is produced. For example, as indicated in Fig. 2, an alcohol dosage of 12.5% and a total water content of-2l% gave about the same extraction of salts and other' impurities (such as green acid soap) as an alcohol dosage of 6.25% and a total water content of 34%. In the first case the yield of brine layer was 8.5% as compared with 10.0% in the second, but the brine in the first case was more concentrated. (Other crude sulfonates will have somewhat diiferent optimum ranges but the appropriate range will be found Within the general order of magnitude indicated for the stock shown above.) While the extraction of impurities was about the same in the two cases, it will be noted that in the rst case only a brine phase separated on settling, yielding two layers, whereas in ythe second case a rejected oil layer appeared on top ofthe concentrated and purified soap layer,

along with the brine layer on the bottom, thereby yielding three layers. Sometimes itis preferable to avoid simultaneous rejection of oil along with the brine, as for example in one method-of operating a continuous extraction column, but in the batch method, simultaneous separation of oil is of little consequence, and the dosages of alcohol and water are chosen to give the optimum extraction of salts and other water-soluble impuritiesV .before any appreciable additional water or alcohol is added, lest the brine redissolve in the mix.

Often, it is desirable to. have present at least enough alcohol to saturate or approximately saturate the water present, in order to get good separation. This is true especially where high 4volume ratios of Water (such as higher than the indicated 60% of water based on the oil-sulfonate content) are used, inasmuch as such saturation provides a good means for alcohol control. Otherwise, good alcohol contents are found in the range of 10% to 50% of the total water content, or within a range of about 3% to 20% based on the oil-sulfonate content. 'Ihe economically and operatively preferred range, if not the most eilicient range, is from 5% to 15% of alcohol or other emulsion-breaking liquid, based on the oilsulfonate content.

In the event the crude sulfonate as received contains too much water to give a brine phase upon theaddition of the specied alcohol, the excess water is removed by evaporation substantially into or, if desired, until the amount remaining corresponds to the working range for the usual alcohol dosage of 5% to 15%. The evaporation may be by distillation or by heating and air blowing. In general the most satisfactory procedure is to remove most of the water and then add back the desired amount as the stock is processed in accordance With this invention.

In purifying crude sulfonates containing a high ratio of soap to oil, it hasbeen found convenient and efficient to add a substantial amount of lubricating oil to the stock or to the mix being treated for the two-fold purpose of reducing the viscosity and reducing the solvent power of the soap phase for water-soluble impurities. As long as the oil added is of suitable quality, this entails little or no hardship because this amount of oil is easilyrejected, after the removal of the brine layer, by addition of water or alcohol and thereby recovered. In this instance the rejected oil may be recycled without removal of dissolved or entrained alcohol and water.

In the foregoing example of a commercial operation of the process, the method of treatment is batchwise for each of the Purification, concentration, and conversion steps. In many instances, however, particularly where the vdemand for the finished sulfonate is steady and of suilcient magnitude, it is desirable to operate the process in a continuous manner.

is then added to bring up e 14 liquid specified herein is charged at a controlled rate through a pump 34 into the line 33 through which the crude sulfonate is flowing. Water or aqueous sodium chloride solution is charged through a pump 35 at a controlled rate also into the line 33 through which the crude sulfonate andvalcohol are flowing. The mixture of crude sulfonate, alcohol and water flows into a mixer 36 which is equipped with suitable agitators and baiies to insure chemical equilibrium of the reactants and reaction products as they emerge from the top of the mixer 36 through a line 31 and flow into a settling vessel or purier 38. In this vessel, the soda brine phase containing sodium sulphite, sodium sulphate and other water-soluble impurities, such as green acid soap, settles to the bottom and the puried sulfonate l rises to the top. The settled soda brine is with- Figure 5 illustrates continuous operation of the Many modifications and combinations drawn through a valve 39 actuated as by a suitable liquid level control device (at the interface) in vessel 38 and sent to an alcohol recovery still where the alcohol is recovered, and the brine is then discarded.

The purified sulfonate practically free of brine `droplets overflows from the tank 38 to a line 40 through which it is forced by a pump 4| into a mixer 42, Water is charged by a pump 43 into the line 40 through which the purified sodium sulfonate is flowing. Mixer 42 is equipped with suitable agitators and bailles to insure equilibrium between the reactants and reaction products by the time they emerge through an upper line 44 and flow into a settling vessel or oil rejector 45. The mixture entering the vessel 45 stratifies into a concentrated soap and oil layer settling tothe bottom and a rejected oil layer rising to the top and removed through an upper line 45a. The concentrated soap layer is transferred from the bottom of the vessel 45 through a lower line 46 by a pump 41 and a valve 48 which are controlled by a suitable liquid level device in the settling vessel 45.' A relatively concentrated calcium chloride solution is charged by a pump 49 into the line 45 through which the concentrated sodium sulfonate is flowing, this stream passing to a converter or mixer 50 equipped with suitable agitators and ballies to insure thorough equilibrium between the reactants and reaction products when the mixture emerges at the top through a line 5l by which it is carried into converted concentrate settling vesel 52. The mixture entering the settling vessel 52 straties into two layers; namely, (l) an aqueous phase containing sodium chloride formed by metathesis from the calcium chloride, excess calcium chloride, and other water soluble impurities such as the last portions of green acid soaps, and (2) an oily phase consisting of oil, converted sulfonate, and the major portion of the alcohol carried through the process to this point.

The oily phase rises to the top of the settling vessel 52 and overflows through a line 53 from which it is charged by pump 53a to an alcohol recovery still 54. A slurry of calcium hydroxide in either oil, water, or calcium chloride solution is prepared in an agitator 55 and pumped via a line 55a and a pump 56 into the line 53 carrying the converted soap layer to the alcohol recovery `still 54. In practice the still 54 is duplicated, one still being used for distillation while the other is being charged, or the converted soap layer supplied by the line 53 is accumulated in anY intermediate storage tank (not shown) While a batch is being run down in the still 54, or the still 54 may be of the' continuous type consisting of a tubular heater and fractionating tower. Either .steam or vacuum or both may be used vin the still to aid removal of the last traces of alcohol and Water from the converted soap layer. The converted soap layer is nally heated to a temperature in the neighborhood of 300 F. and then viiltered in a filter press 51 and sent to storage 58. To aid filtration of the dehydrated calcium soap concentrate, a small amount of diatoma- .ceous earth (e. g. Supercel Hyflo) such as 1% to 2% by weight, is added before filtration. The alcohol from the converted soap layer is recovered in apparatus 59 for reuse in the process.

Inasmuch as the process depends upon the presence of water in the various steps, it is unnecessary to remove the dissolved water from the alcohol recovered from any step in the process. The water layer from the condenser of the alcohol recovery system is occasionally rerun to concentrate the alcohol.

Since the rejected oil layer rising in the settling and rejecting Vessel 45 contains a small amount of sodium mahogany soap which should 4be converted, such oil is passed by the line 45a from the vessel 45 to a mixer 60 equipped with suitable agitators and bailes to insure equilibrium between reactants and reaction products. Since the bottom aqueous layer in the settling vessel 52, resulting from the reaction of the concentrated soda soap with calcium chloride solution, contains excess calcium chloride, this brine layer also is pumped to the mixer 65 for the purpose of reaction with the soda soap in the rejected oil. This transfer is made by way of a line 6|, a Valve Bla, and a pump lb controlled by a suitable liquid level device (not shown) in the vessel 52. The brine from the line 6I is delivered to the line 45a through which the rejected oil is being forced to the mixer 60 by a pump 50a. Following reaction between calcium chloride and the sulfonate of the rejected oil in the mixer 60, the reacted materials leave the mixer ,60 by a line 62 and now into a settling vessel 63 Where stratification occurs to yield a calcium brine layer on the bottom and a converted oil layer on top. The converted oil layer is delivered by a line' 5d and a pump Ella to ad still 65 for recovery of contained alcohol and dehydration of the oil. The calcium brine layer is withdrawn from the bottom of the vessel 53 through suitable level control valves and pumps (not shown) and is processed for recovery of dissolved alcohol and then discarded. A small portion of this brine can be used in the agitator 55, if desired, in making a calcium hydroxide slurry to be added either to the concentrated soap layer being charged to the still 54 or to the converted, rejected oil layer charged to the still t5. The converted byproduct oil layer, in which any trace of soap carried over from the concentration of the soda soap in the settling and rejecting vessel 45 has now been converted in the vessel S3 to calcium soap, when being processed in the still 65 may contain a slurry of calcium hydroxide suspended in oil or water or brine containing calcium chloride added from the agitator 55, as above indicated, or from an agitator 66 by a pump 51 via a line 58, to the charge going into the still 65. In this still, both dissolved alcohol and Water are removed by heating to a temperature in the neighborhood of 300 F. with the use of vacuum or steam. The liberated alcohol is recovered in appropriate apparatus 69 for reuse in the process. The dehydrated alcohol-free oil is filtered and sent to storage for use in blending lubricating foils, rust preventives, :and the like,-or-it='may be further rened to produce White oils.

Inthe operation illustrated in Fig. 5the temperature is preferably higher than in the batch method illustrated in Fig. 1, to insure efficient operation of the continuous settling vessels; namely, in the neighborhood of F. to 200;F. as previously indicated. Appropriate heaters (not shown) are employed in much the same way as shown in Fig. 1. Care Yis taken to avoid loss of alcohol by vaporization, Aeven to thepoint of operating all mixers. and settlers under pres- Sure.

Alcohols boiling higher than secondary butyl alcohol, especially methyl isobutyl carbinol, are often preferred in the continuous method :of

operating the process at the higher temperature. l

Methyl isobutyl carbinol is available commercially at only slightly higher cost'than secondary butyl alcohol and is readily recovered 'fromthe various brines and products, its boiling point being 267 F. at atmospheric pressure. Also the solubility of the higher boiling alcohols in Water is less, methyl isobutyl carbinol being soluble in Water to the extent of only about 2% as compared with about 12% for secondary butyl alcohol.

The lower solubility in Water of amyl and hexyl alcohols is also desirable in the countercurrent methods of operating the process, about to Vbe described, particularly in the countercurrent washing of the rejected oil to reduce dissolved soap content, as well as in the purification and conversion steps where water or aqueous solutions are passed in countercurrent to the oily phases. Higher temperatures, e. g. '180 F. to 200 F., with operation under pressure are employed in such countercurrent operations in much the same manner as for the process of Fig. 5.

Fig. 6 illustrates a countercurrent, continuous operation of the process, the crude sulfonate in storage tank 1I being fed by a pump 12 at a controlled rate through a, line 13 to the processing system. The alcohol or other emulsion-breaking liquid specified herein is charged at a controlled rate by a pump 14 into the line 13 through which the crude sulfonate is flowing. The mixture of stock and alcohol enters the lower portion of a countercurrent extraction column 15 while water or aqueous sodium chloride is charged at a controlled rate by a pump 16 anda line 11 into the upper portion of the extraction column 15. As the mixture of stock and alcohol works its way up the column, the water orsodium chloride solution Works its Yway downward land extracts from the stock the Water soluble impurities such as sodiumsulphate, sodium sulphite and the green acid soaps. 'I'he brine thus formed settles in the bottom of the column 15 and is withdrawn through a valve 18 which is actuated by a suitable level control in the column 15 and is sent to a still for recovery of the alcohol dissolved therein. The extracted or puried stock containing the bulk of the alcohol introduced into the stream of stock in the line 13, passes out of the top of the column 15 lthrough a line 19 and is forced by a pump 80 through a line 8l either directly into an oil rejection or extraction column 82 or via an agitator 83 by proper manipulation of valves 84, 85,and 85. Water-is charged into the system at a controlled rate by a pump 88 through a line S9 by opening a valve '90, and/or water is charged at a controlled rate into the top section of the column 82 by a pump 9| via a valve 52 and a line Y93. Water charged through the line 89 mixes with the purified stock and alcohol in the line 8 I. This mixturemay be thoroughly agitated by closing the valve 84 and opening the valves 85 and 86 and forcing the mixture through the agitator 83 which provides sufficient agitation to insure equilibrium between the reactants and the reaction products; this usually being preferred when water is introduced by the pump 88 and line 89 into the stream being processed. Sometimes it is desirable to introduce all of the water via the pump 9| and line 93 into the top section of the column 82, in which case the stock flowing in the line 8| is made to bypass the agitator 83 by opening the valve 84 and closing the valves 85 and 85. The water introduced into the top section' of the extraction column 82 via line 93'washes countercurrently the rejected oil which is rising upward in the column 82, and also causes rejection of oil from the purified stock in the lower section of the column 82.

In other Words, partial or fairly complete rejection of oil may be accomplished by the water introduced along with the stock via the line 8| and agitator 83, while any water introduced into the upper section of the column 82 via the line 93 serves to wash out soap dissolved or entrained in the rejected oil rising from the bottom of the column.

The soda soap solution now concentrated with respect to oil settles to the bottom of the column 82 and is removed via a valve 94 and a pump 95 which are actuated by a suitable level control device (not shown) in the lowest section of the column 82. The concentrated soda soap solution is forced by the pump 95 via a line 96 into the bottom section of a conversion or extraction column 91, going through an agitator 98 or by-passing `this agitator by proper operation of valves 99, |88, and lili. Aqueous calcium chloride solution of suitable concentration is charged Ainto the column 91 by a pump |92 via a line |83 into the top section of the extraction column 91, or by a pump |09 into the bottom section of the column 91 in admixture with the concentrated soap stock movingin the line 9E. If calcium chloride solution is introduced into the line 96, it is desirable to agita-te the resulting mixture thoroughly before it reaches the column 91 by sending it through the agitator 98 by opening the valves |88 and mi and closing the valve 99. If a portion of the calcium chloride solution is premixed with the stock in the agitator 98 and introduced into the bottom section of the column 91, via the line 99 along with the stock, any additional calcium chloride solution introduced by the pump |82 moves countercurrent to the reacted oily soap phase rising in the column 91 and serves to complete the conversion of sodium soap to calcium soap. The converted soap 'phase ilows out the top of column 91 via a line |85 and a pump |86 and is `sent to intermediate storage tank |81 whence it is sent to a still |88, for recovery of alcohol in apparatus |09, and dehydration before filtering. Lime or other reagents may be added to the stock in the tank |81 before it is charged to the still `|98 by a pump H8. Diatomaceous earth which serves as a filter aid is added before, during, or after the distillation and dehydration. The dehydrated concentrate is passed through a iilter and the finished calcium sulfonate concentrate is sent to storage l2.

The spent or partially spent calcium chloride brine resulting from the conversion of the soda soap to calcium soap in the agitator 98 and con version or extraction column 91, settles to the bottom of the column 91, whence it is withdrawn through a valve I3 and pump Iii and sent to a still for recovery of dissolved alcohol.

The oil rejected in the rejection column 82 rises upward and settles practically free of en'- trained water and soap in the top of the column. However it contains a very small proportion of dissolved mahogany soap which should be converted. Therefore, the rejected oil is passed from the top of the column 82 via a line |5 and a pump l5 into a treating column H8, and calcium chloride solution, which may conveniently be the partially spent brine layer settling to the bottom of extraction column 91, also is introduced into the top of column IIS via a pump ||9 and a line |28, or into the bottom 'of the column H8 via a pump I2! and a line |22. Any calcium chloride solution introduced via pump ||9 is best mixed with the rejected oil phase flowing in the line I |5 by passing the mixture through an agitator |29 before it goes into the treating column |8. The operation of the conversion of the small amount of soda soap carried over in the by-product oil flowing from the top of the rejection column 82 is similar to the conversion of the concentrated soda soap phase settling to the bottom of the column 82 and converted and separated in the column 9-1.

The converted, rejected oil in the column ||8 rises to the top and is sent via a pump |24 and a line |2l|uJ to intermediate storage |25, whence it is charged by a pump |29 to a still |28 for alcohol recovery in apparatus |29 and for dehydration before filtering. After passing through a filter, this converted, rejected oil is sent to storage for use as a. lubricant, or in compounding rust preventives or lubricants, or the like. The brine phase in the columnl ||8 settles to the bottom and is withdrawn via a valve |3I and a pump |32 which are controlled by a suitable liquid level device (not shown) in the lowest portion of the column H8. This brine is distilled for alcohol recovery and is iinally discarded.

It is to be understood that this process, whether batch or continuous, is equally applicable to the treatment of alkali-metal sulfonate-oil concentrates of commerce which contain around 30% to 68% sulfonates and 40% to Y10% oil with impurities in the form of green acid soaps, sulfates, sultes, and the like. f

While the puried polyvalent metal petroleum sulfonates or mahogany soaps obtained in accordance with this invention are usually calcium products, the invention, nevertheless extends to the preparation of other alkaline earth metal sulfonates, especially barium and strontium salts. These may be prepared with water-soluble salts of barium and strontium as readily as the calcium product is produced. The process is also applicable to the production of. other water-insoluble, oil-soluble sulfonates, and these may include the mahogany acid salts of aluminum, zinc, magnesium, lead, cobalt, nickel, and the like.

Concentrates of the above nature may be put to various uses. For example, the addition of 5% V4to 20% of the above concentrate to calcium,

obtained by diluting the appropriate polyvalentmetal sulfonate concentrate With appropriate carriers, such as any mineral oil lubricating fraction suitable for the ultimate use of the product. Commonly, such dilution will yield a sulfonate content between about .05% and about 6% in the blended product. Ordinarily a satisfactory working proportion is about 3% of sulfonate, or within a rangeof about 2% to about 4%.

Another important use of the purified, polyvalent-metal sulfonate of this invention is in connection with the production of lubricating oils for severe service, internal combustion engines, such as aircraft and other heavy-duty engines, including diesel engines. Here the sulfonate may be present in proportion to impart rust-preventive characteristics or for other purposes, including promotion of detergent and Wear-reducing characteristics. For these purposes, typical lubricating oils may contain from about 0.5% to as much as 10%, for example 3%, of the purified alkaline earth metal sulfonates of this invention, together with such other additive constituents as may be deemed desirable. Depending upon the ends sought, such other materials may include sulfurized alcohols, sulfurized hydrocarbons, thiophosphates, phenolic thioethers, phosphites, metal derivatives of these materias, varous oil-soluble detergent soaps, such as the calcium soaps, and similar metal soaps of synthetic carboxylic acids obtained from the oxidation of parrainic hydrocarbons, and kindred materials known in the lubricating industry.

When any of the products above described are to be used under conditions where foaming is apt to be encountered, purified sulfonates may be produced, as above described, by employing the indicated octyl alcohol and terminating the subsequent expulsion of the octyl alcohol so as to leave around 0.5% to 2% of octyl alcohol in the oil-sulfonate solution whereby to impart antifoaming characteristics. The same will be true of any other organic solvent which is employed and possesses anti-foaming characteristics. I have also found that the presence of 0.25% to 2% of octyl alcohol or other high molecular weight alcohol in the nished lubricant increases very greatly the effectiveness of the sulfonate addition in combating corrosion from hydrobromic acid. For example, the addition of 2.5% calcium sulfonate to a heavy-duty motor oil containing 0.75% calcium soap of oxidized petroleum acids and 0.75% calcium salt of tertiary amyl phenol sulfide was sufcient to protect the crankcase interior of engines against rusting from moisture condensation, but was insufficient to vprotect against diluteaqueous hydrobromic acid. The addition of 0.75% of octyl alcohol (2-ethylhexanol) to the foregoing oil containing 2.5% sulfonate, as described, gave perfect protection against hydrobromic acid corrosion.

While I have described my process as being applicable to petroleum sulfonates produced by sulfuric acid treatment of petroleum fractions particularly those in the lubricating oil range, my process is also applicable to sulfonates produced synthetically by sulfonation of hydrocarbons or other compounds from coal tar products or any other source. Also, my process is applicable to sulfates (often called sulfonates) produced by reacting sulfuric acid or sulfur trioxide with alcohols and/or unsaturated compounds belonging to the classes of hydrocarbons, acids, esters, ketones, ethers, glycerides, waxes, etc.

Inasmuch as variations of the different fea-1 20` tures of the generic invention herein disclosed will no doubt occur to those skilled in this particular art, it is intended to cover all modifications which fall within the scope of the patent claims.

I claim as my invention:

1. The process of treating a material consisting of a major proportion of hydrocarbon oil containing alkali metal mahogany sulfonates, alkali metal green acid sulfonates and watersoluble inorganic sulfate and sulte, which comprises: forming a mixture consisting essentially of said hydrocarbon oil, said alkali metal mahogany sulfonates, said alkali. metal green acid sulfonates, said water-soluble inorganic sulfate and sulflte, at least l0 parts by volume of water per 100 parts by volume of said hydrocarbon oil and sulfonates and at least 5 parts by volume per 100 parts by volume of said hydrocarbon oil and sulfonates of a hydrocarbon oil-soluble emulsion breaking liquid selected from the group consisting of butyl, amyl and hexyl alcohols, the amounts of said water and said emulsion breaking liquid being sufficient to produce three separable phases, a concentrated mahogany sulfonate phase containing hydrocarbon cil, water and emulsion breaking liquid, a hydrocarbon oil phase rejected from said concentrated mahogany sulfonate phase and an aqueous phase containing alkali metal green acid sulfonates and watersoluble inorganic sulfate and sulte; and separating said three phases from each other.

2. The process as dened in claim 1 in which the temperature of said hydrocarbon oil phase and said concentrated sulfonate phase during said separating is between 140 F. and 200 F.

3. The process as dened in claim 1 in which the emulsion breaking liquid is a butyl alcohol.

4. The process as dened in claim 1 in which the emulsion breaking liquid is secondary butyl alcohol.

5. The process as defined in claim 1 in which the emulsion breaking liquid is hexyl alcohol.

6. The process as defined in claim 1 in which a water-soluble polyvalent metal salt is mixed with the separated concentrated mahogany sulfonate phase to convert the alkali metal mahogany sulfonate therein to a polyvalent metal inahogany sulfonate and produce a separable aqueous phase and a concentrated polyvalent metal mahogany sulfonate phase containing hydrocarbon oil and minor proportions of water and emulsion breaking liquid and the separable aqueous phase is separated from said concentrated polyvalent metal mahogany sulfonate phase.

7. The process of treating a material consisting of a major proportion of hydrocarbon oil containing alkalimetal mahogany sulionates, alkali metal green acid sulfonates and water-soluble` inorganic sulfate and sulte, which comprises: forming a mixture consisting essentially of said hydrocarbon oil, said alkali metal mahogany sulfonates, said alkali metal green acid sulfonates,

ing hydrocarbon oil, water and emulsion breaking liquid, a hydrocarbon oil phase rejected from said concentrated mahogany sulfonate phase and an aqueous phase containing alkali metal green acid sulfonates, Water-soluble inorganic sulfate and sulte and a major proportion of said sodium chloride and separating said three phases from each other.

8. The process as dened in claim 7 in which a Water-soluble polyvalent metal salt is mixed with the separated concentrated mahogany sulfonate phase to convert the alkali metal mahogany sulfonate therein to a polyvalent metal mahogany sulfonate and produce a separable aqueous phase and a concentrated polyvalent metal mahogany sulfonate phase containing hydrocarbon oil and minor proportions of Water and emulsion breaking liquid and the separable aqueous phase is separated from said concentrated polyvalent metal mahogany sulfonate phase.

9. The process of treating a material consisting of a major proportion of hydrocarbon oil containing alkali metal mahogany sulfonates, alkali metal green acid sulfonates and Water-soluble inorganic sulfate and sulflte, which comprises: forming a mixture consisting essentially of said hydrocarbon oil, said alkali metal mahogany sulfonates, said alkali metal green acid sulfonates, said Water-soluble inorganic sulfate and sulte, at least 10 parts by volume of Water per 100 parts by volume of said hydrocarbon oil and sulfonates and at least parts by volume per 100 parts by volume of said hydrocarbon oil and sulfonates of a hydrocarbon oil-soluble emulsion breaking liquid selected from the group consisting of butyl, amyl and hexyl alcohols, the amounts of said Water and said emulsion breaking liquid being suicient to produce an aqueous phase containing alkali metal green acid sulfonates and Watersoluble sulfate and sulte, and a separable hydrocarbon oil-sulfonate phase containing hydrocarbon oil, water, emulsion breaking liquid and alkali metal mahogany sulfonates; separating said hydrocarbon oil-sulfonate phase from said aqueous phase; mixing with the separated hydrocarbon oil-sulfonate phase an additional amount of a liquid selected from the group consisting of Water, and said emulsion breaking liquid, the amounts of said Water and said emulsion breaking Y liquid in the resulting mixture being suiicient to produce a concentrated mahogany sulfonate phase containing alkali metal Vmahogany sulfonates, hydrocarbon oil, Water and emulsion breaking liquid and asepa'rable hydrocarbon oil phase rejected from said concentrated mahogany sulfonate phase; and separating said hydrocarbon oil phase from said concentrated mahogany sulfonate phase.

10. The process as defined in claim 9 in which the emulsion breaking liquid is a butyl alcohol.

11. The process as defined in claim 9 in which the emulsion breaking liquid is secondary butyl alcohol.

12. The process as defined in claim 9 in which the emulsion breaking liquid is hexyl alcohol.

13. The process of treating a material consisting of a major proportion of hydrocarbon oil containing alkali metal mahogany sulfonates, alkali metal green acid sulfonates and water-soluble inorganic sulfate and sulte, which comprises:

forming a mixture consisting essentially of said hydrocarbon oil, said alkali metal mahogany sulfonates, said alkali metal green acid sulfonates, said water-soluble inorganic sulfate and suliite, sodium chloride, at least 10 parts by volume of Water per 100 parts by volume of said hydrocarbon oil and sulfonates and at least 5 parts by volume per 100 parts by volume of said hydrocarbon oil and sulfonates of a hydrocarbon oilsoluble emulsion breaking liquid selected from the group consisting of butyl, amyl and hexyl alcohols, the amounts of said water, said sodium chloride and said emulsion breaking liquid being suicient to produce an aqueous phase containing alkali metal green acid sulfonates, Watersoluble sulfate and sulte and said sodium chloride, and a separable hydrocarbon oil-sulfonate phase containing hydrocarbon oil, water, emulsion breaking liquid and alkali metal mahogany sulfonates; separating said hydrocarbon oil-sulfonate phase from said aqueous phase; mixing with the separated oil-sulfonate phase an additional amount of a liquid selected from the group consisting of Water, and said emulsion breaking liquid, the amounts of said Water, said sodium chloride and said emulsion breaking liquid in the resulting mixture being sufficient to produce a concentrated mahogany sulfonate phase containing alkali metal mahogany sulfonates, hydrocarbon oil, water and emulsion breaking liquid and a separable hydrocarbon oil phase rejected from said concentrated mahogany sulfonate phase; and separating said hydrocarbon oil phase from said concentrated mahogany sulfonate phase.

14. The process as dened in claim 13 in which the emulsion breaking liquid is a butyl alcohol.

15. The process as defined in claim 13 in which the emulsion breaking liquid is secondary butyl alcohol.

16. The process as dened in claim 13 in which the emulsion breaking liquid is hexyl alcohol.

17. The process as defined in claim 13 in Which a Water-soluble polyvalent metal salt is mixed with the separated concentrated mahogany sulfonate phase to convert the alkali metal mahogany sulfonate therein to a polyvalent metal mahogany sulfonate and produce a separable aqueous phase and a concentrated polyvalent metal mahogany sulfonate phase containing hydrocarbon oil and minor proportions of Water and emulsion breaking liquid and the separable aqueous phase is separated from said concentrated polyvalent metal mahogany sulfonate phase.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,901,383 Voogt Mar. 14, 1933 2,079,443 Fulton May 4, 1937 2,084,506 Rosen June 23, 1937 2,168,315 Blumer Aug. 8, 1939 2,204,969 Percy June 18, 1940 2,246,374 Lohman June 17, 1941 Y2,373,793 Susie Apr. 17, 1945 2,406,763 Griesinger Sept. 3, 1946 2,453,690 Bray Nov. 16, 1948 2,522,212 Dammers Sept. 12, 1950 

1. THE PROCESS OF TREATING A MATERIAL CONSISTING OF A MAJOR PROPORTION OF HYDROCARBON OIL CONTAINING ALKALI METAL MAHOGANY SULFONATES, ALKALI METAL GREEN ACID SULFONATES AND WATERSOLUBLE INORGANIC SULFATE AND SULFITE, WHICH COMPRISES: FORMING A MIXTURE CONSISTING ESSENTIALLY OF SAID HYDROCARBON OIL, SAID ALKALI METAL MAHOGANY SULFONATES, SAID ALKALI METAL GREEN ACID SULFONATES, SAID WATER-SOLUBLE INORGANIC SULFATE AND SULFITE, AT LEAST 10 PARTS BY VOLUME OF WATER PER 100 PARTS BY VOLUME OF SAID HYDROCARBON OIL AND SULFONATES AND AT LEAST 5 PARTS BY VOLUME PER 100 PARTS BY VOLUME OF SAID HYDROCARBON OIL AND SULFONATES OF A HYDROCARBON OIL-SOLUBLE EMULSION BREAKING LIQUID SELECTED FROM THE GROUP CONSISTING OF BUTYL, AMYL AND HEXYL ALCOHOLS, THE AMOUNTS OF SAID WATER AND SAID EMULSION BREAK ING LIQUID BEING SUFFICIENT TO PRODUCE THREE SEPARABLE PHASES, A CONCENTRATED MAHOGANY SULFONATE PHASE CONTAINING HYDROCARBON OIL, WATER AND EMULSION BREAKING LIQUID, A HYDROCARBON OIL PHASE REJECTED FROM SAID CONCENTRATED MAHOGANY SULFONATE PHASE AND AN AQUEOUS PHASE CONTAINING ALKALI METAL GREEN ACID SULFONATES AND WATERSOLUBLE INORGANIC SULFATE AND SULFITE; AND SEPARATING SAID THREE PHASES FROM EACH OTHER. 